1. Field of the Invention
The present invention relates to a method for manufacturing a cylindrical member having a coating on an outer peripheral surface of a mandrel using a ring-shaped coating head.
2. Description of the Related Art
In a known method for manufacturing a cylindrical member having a coating on a peripheral surface of a mandrel, a coating liquid is applied on an outer periphery of the mandrel using a ring-shaped coating head having an annular slit opening in an inner peripheral surface (see Japanese Patent Application Laid-Open No. 2007-130589). Such a method for manufacturing a cylindrical member is applied to, for example, manufacture of an elastic roller which can favorably be used in an electrophotographic apparatus having an elastic layer containing silicone rubber on a peripheral surface of a mandrel.
After application of a coating liquid to a peripheral surface of one mandrel, discharge of the coating liquid from a ring-shaped coating head needs to be temporarily stopped in order to place a next mandrel on the ring-shaped coating head. As one problem of the above described method, when an annular slit is being separated from the coated mandrel, the coating liquid is stretched over both the slit and the coated mandrel, and the coating liquid adheres to and remains on around the slit.
Thus, in an intermittent application of the coating liquid with the ring-shaped coating head as described above, a coating liquid adhered to and remained on a slit portion of a coating head, needs to be removed before start or after finish of application of the coating liquid.
Japanese Patent Application Laid-Open No. 2007-130589 discloses a method for cleaning the annular slit. In this method, a detachable ring member is attached to the slit portion of the ring-shaped coating head, and, after application, the ring member is moved perpendicularly to a surface in which the annular slit opens, that is, the inner peripheral surface of the ring-shaped coating head. Thus, a coating liquid remained on the annular slit portion is adhered to the ring member. The ring member is taken out to clean the annular slit.
However, in the method described in Japanese Patent Application Laid-Open No. 2007-130589, the detachable ring member is taken out from a coating device together with the coated mandrel, and thus the ring member needs to be changed for each application. Thus, one application to the mandrel requires one ring member. Also, a mechanism for attaching and detaching the ring member to and from a coating device body is required.